GROWTH AND IMMUNE RESPONSE OF AFRICAN CATFISH Clarias gariepinus (Burchell, 1822) FED DIETARY IRON-OXIDE NANOPARTICLES OF ALOE VERA EXTRACT AND CHALLENGED WITH Aeromonas hydrophila

Abstract

Minerals and nutrients synthesized at nano size from extracts of plants with medicinal properties have been shown to have beneficial impact on growth, immune-stimulation and overall health of fish and with limited environmental impact due to their biodegradability. Thus, this study evaluated the growth efficacy, haematology and immunity of Clarias gariepinus fed diets fortified with iron-oxide Aloe vera (Aloe barbadensis) leaf extract (AvFeONps). The green synthesized AvFeONPs were confirmed by ultraviolet-visible (UV-Vis) spectroscopy as nano-particles by its wavelength. Different concentrations of the biosynthesized AvFeONPs (0.0, 0.4, 0.8, 1.2 and 1.6g/kg feed) were added into the basal diet used for feeding C. gariepinus for 84 days. The results showed significant differences (P< 0.05) in weight gain (WG) of the fish fed AvFeONPs supplemented diets in comparison with the fish fed the control diet (0.0g/kgAvFeONPs). Fish fed 1.6g/kg of AvFeONPs had the highest weight gain of 102.12g while fish fed the control diet had the least mean weight gain of 73.87g. The specific growth rate of 3.25% recorded in the control group was statistically lower than the values from fish fed AvFeONPs supplemented diets 3.33 - 3.74%. Dietary AvFeONPs resulted in significant increases in the GP, catalase, and total serum protein; and significant reduction in ALT, AST, SOD, cholesterol and serum glucose levels. The PCV, RBC and WBC also increased (P<0.05) in the fish fed diets supplemented with AVFeONPs, which consequently led to increased survival in the fish when challenged with a pathogen, Aeromonas hydrophila.